Crash when creating child nodes from and loading program - Custom API

URCap Development
5

Hi @ajp

What I implemented is the following:

Node contribution:

public class MyNodeToAddAndRemoveContribution implements ProgramNodeContribution, MyNodeToAddAndRemoveCustomAPI
{
// this is my node contribution
}

Node custom api interface:

public interface MyNodeToAddAndRemoveCustomAPI
{
// this is my custom api interface
// I have myself nothing inside this interface
}

  • In my root node, from which I will be able thanks to a checkbox to add and remove the node mentioned previously:
  1. I am using the ProgramNodeVisitor to retrieve the index of the MyNodeToAddAndRemove in my program hierarchy:

private int getMyNodeToAddAndRemoveIndex()
{
final int childIndex = new int[1];
childIndex[0] = -1;

TreeNode root = apiProvider.getProgramAPI().getProgramModel().getRootTreeNode(this);

root.traverse(new ProgramNodeVisitor()
{
  @Override
  public void visit(URCapProgramNode programNode, int index, int depth)
  {
    if(programNode.canGetAs(MyNodeToAddAndRemoveCustomAPI.class))
    {
      //System.out.println("Index: " + index);
      childIndex[0] = index;
    }
  }
});

// return -1 if the node does not exist
return childIndex[0];

}

  1. When the user enables or disables the check box:

public void setMyNodeToAddAndRemoveState(final boolean state)
{
this.undoRedoManager.recordChanges(new UndoableChanges()
{
@Override
public void executeChanges()
{

    // set the model state accordingly here
   // ...

    TreeNode root = this.programAPI.getProgramModel().getRootTreeNode(this);

    if (state)
    {
      // add the node (in try-catch)
      if (ProgramNodeHelper.getChildrenNb(root) > 0)
        root.insertChildBefore(root.getChildren().get(0), this.programNodeFactory.createURCapProgramNode(MyNodeToAddAndRemoveService.class));
      else
        root.addChild(this.programNodeFactory.createURCapProgramNode(MyNodeToAddAndRemoveService.class));
    }
    else
    {
      // remove the node (in try-catch)
      int myIndex = this.getMyNodeToAddAndRemoveIndex();
      if (myIndex < 0)
            return;
      root.removeChild(root.getChildren().get(myIndex));
    }
  }
});

}

  1. If some sub nodes must be added anyway and are not interactable through checkboxes, they must be added from the root node constructor only if the context is a node creation:

public MyRootNodeContribution(ProgramAPIProvider apiProvider, MyRootNodeView view,
DataModel model, CreationContext context)
{
// constructor
// do something
if (context.getNodeCreationType() == NodeCreationType.NEW)
{
TreeNode root = this.programAPI.getProgramModel().getRootTreeNode(this);
// in a try-catch
root.addChild(this.programNodeFactory.createURCapProgramNode(MyPermanentNodeService.class));
}
}

Sorry for the bad indentation. Other than that, that should do the trick. Let me know if you have any questions.

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